Gasoline production

ABSTRACT

A process for producing a high octane unleaded or low lead content gasoline which comprises (a) oxidizing isobutane in the presence of acetic acid to obtain tertiary butyl alcohol containing acetic acid, (b) separating a portion of the acetic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing residual amounts of acetic acid, (c) contacting the tertiary butyl alcohol containing residual amounts of acetic acid with an acidic ion exchange resin catalyst to catalyze the esterification reaction of the residual amounts of acetic acid with tertiary butyl alcohol to obtain t-butyl acetate and water with unreacted tertiary butyl alcohol, (d) blending the mixture of tertiary butyl alcohol containing t-butyl acetate and water with gasoline boiling range hydrocarbons, and (e) separating water from the blend to obtain a high octane gasoline.

United States Patent Sieg et al.

Sept. 2, 1975 GASOLINE PRODUCTION [75] Inventors: Robert P. Sieg, Piedmont; Robert H.

Kozlowski, Berkeley, both of Calif.

[73] Assignee'. Canadian Industries Ltd., Montreal,

Canada [22] Filed: Jan. 21, 1971 [2]] Appl. No.: 108,533

[52] US. Cl 44/56; 44/70 [SI] Int. Cl. C10L 1/02; CIOL H18 [58] Field of Search 44/56, 70

[56] References Cited UNITED STATES PATENTS 2,085,499 6/1937 James 44/56 X 2,128,910 9/l938 Bludworth 44/54 X 2,228,662 l/194l Holm 44/70 X 2,334,006 11/1943 Holm 44/70 2,827,500 3/l958 Bloecher et al,. 260/641 3,007,782 ll/l96l Brown et al. 44/56 3,082,070 3/1963 Eckert 44/70 X 3,l68,385 2/1965 Giammaria et al. 44/56 Primary Examiner-W. J. Shine Attorney, Agent, or F irm-Cushman, Darby & Cushman A process for producing a high octane unleaded or low lead content gasoline which comprises (a) oxidizing isobutane in the presence of acetic acid to obtain tertiary butyl alcohol containing acetic acid, (b) separating a portion of the acetic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing residual amounts of acetic acid, (c) contacting the tertiary butyl alcohol containing residual amounts of acetic acid with an acidic ion exchange resin catalyst to catalyze the esterification reaction of the residual amounts of acetic acid with tertiary butyl alcohol to obtain t-butyl acetate and water with unreacted tertiary butyl alcohol, (d) blending the mixture of tertiary butyl alcohol containing t-butyl acetate and water with gasoline boiling range hydrocarbons, and (e) separating water from the blend toobtain a high octane gasoline.

ABSTRACT 7 Claims, 1 Drawing Figure 2 7 I0 I a\ c s I O; BUTANE I BUTYL ALCOHOL Ic TION OXIDATION SEPARAT ON ACETIC ACID ESTER": A

CATALYST ACETIC ACID/ 9 ACETIC ACID 2\ BUTYL ALCOHOL, BUTYL ACETATE, WATER BLENDING AND E HYDROCARBON SEPARAHON HIGH OCTAN E GASOLINE I WATE R GASOLINE PRODUCTION BACKGROUND OF THE INVENTION The present invention relates to the production of improved gasolines. More particularly, the present invention relates to the production of relatively high octane gasolines containing no lead additives or only relatively low amounts of lead additives. Still more particularly, the present invention relates to a process combination to produce a gasoline containing tertiary butyl alcohol and tertiary butyl acetate with no more than trace amounts of organic acid impurities.

The use of alcohols in gasoline boiling range hydrocarbons to improve the octane rating of the gasoline has been disclosed previously. For example, US. Pat. No. 2,128,910 discloses the use of methanol and ethanol in gasoline together with propanol and butanol to aid in keeping the methanol and ethanol in solution with the gasoline. US. Pat. No. 2,408,999 also discloses the use of alcohols having three to five carbon atoms as blending components for gasoline.

Production of C alcohols by oxidation of butane using a homogenous catalyst is disclosed in U.S. Pat. No. 2,265,948, US. Pat. No. 2,492,985, US. Pat. No. 2,659,746, and 2,704,294, the disclosures of which patents are incorporated by reference into the present specification. According to US. Pat. No. 2,492,985, the oxidation of butane is carried out substantially completely in the vapor phase using a catalytic liquid in the form of a thin film which is preferably flowing. The catalytic liquid forming the film may itself be a catalyst or it may comprise a carrier liquid containing a catalyst either in suspension or solution.

A carrier liquid for the butane oxidation catalyst is preferably inert to oxidation or is similar or identical to one or more of the oxidation resistant products of the oxidation. Acetic, propionic, or butyric acids, carbon tetrachloride, benzene, phenylacetic acid, acetic anhy dride, water and the like may be used as a carrier liquid for organic or inorganic salts or oxides of cerium, cobalt, copper, manganese, silver or uranium; or other liquids or catalysts such as those disclosed in Pat. No. 2,265,948 issued to D. J. Lodcr on Dec. 9, 1941, may be used.

U.S. Pats. Nos. 2,228,662 and 2,334,006 disclose the use of an ester in gasoline boiling range hydrocarbons to improve the octane rating of the gasoline in the presence of little or no metallo-organic lead additives. Ac cording to these two patents, particularly advantageous results are achieved by adding the esters to isoparaffinic hydrocarbons. According to US. Pat. No. 2,228,662, the esters which may be blended with the isoparaffins are the saturated aliphatic esters of monocarboxylic acids containing from three to seven carbon atoms per molecule and boiling over the range from 130 to 300F. Examples are methyl acetate, methyl propionate, methyl normal butyrate, methyl isobutyrrating of motor fuels, particularly those containing aromatic and/or olefinic components, is improved by the addition of a small amount of a mixture of a hydrocarbyl monocarboxylic acid or a tertiary alkyl ester thereof and an aliphatic alcohol. US. Pat. No. 3,082,070 is directed to the use of substantial amounts of monocarboxylic acid or tertiary alkyl ester in order to increase the octane rating of gasoline fuels. US. Pat. No. 3,082,070 does not disclose an overall process or process combination for obtaining an alcohol-estergasoline fuel mixture and does not disclose a combination process for obtaining such a fuel mixture with no more than trace amounts of organic acid impurities.

SUMMARY OF THE INVENTION According to the present invention, a process is provided for producing a high octane unleaded or low lead content gasoline containing no more than trace amounts of acetic acid, which process comprises (a) oxidizing isobutane in the presence of acetic acid to obtain tertiary butyl alcohol containing acetic acid, (b) separating a portion of the acetic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing residual amounts of acetic acid, (c) contacting the tertiary butyl alcohol containing residual amounts of acetic acid with an acidic ion exchange resin catalyst to catalyze the esterification reaction of the residual amounts of acetic acid with tertiary butyl alcohol to obtain t-butyl acetate and water with unreacted tertiary butyl alcohol, (d) blending the mixture of tertiary butyl alcohol containing t-butyl acetate and water with gasoline boiling range hydrocarbons, and (e) separating water from the blend to obtain a high octane gasoline. It is also particularly preferred to carry out isobutane oxidation in the presence of propionic acid and separate the propionic acid as is the case of acetic acid above.

In broad scope, the process combination concept of the present invention can be applied to removing organic acids from various alcohols formed by oxidation in the presence of an organic acid wherein such alcohols are intended to be blended with gasoline boiling range hydrocarbons, and wherein the acid is removed at least in part by esterification. However, the process of the present invention has particular application and is most preferably applied to isobutane oxidation carried out'in the presence of a catalyst containing propionic or acetic acid because, among other reasons, (1) the partial oxidation of isobutane in the presence of a catalyst containing propionic or acetic acid has been found to be a particularly attractive means of obtaining tertiary butyl alcohol, (2) tertiary butyl alcohol is a relatively high octane gasoline blending component, (3) in producing tertiary butyl acetate or propionate by esterification of small amounts of the acid present as an impurity in the tertiary butyl alcohol produced by isobutane oxidation the dual advantage is achieved of simultaneously removing the acid impurity while producing a high octane gasoline blending component, namely, tertiary butyl acetate or propionate, and (4) isobutane is frequently present in excess in refinery plants because of the large amount of isobutane produced in hydrocracking operations in most refineries. so that the process of the present invention advanta geously is carried out in combination with hydrocracking with the isobutane feedstock being obtained from hydrocracking and, preferably, at least a portion of the gasoline boiling range hydrocarbons also being obtained from the hydrocracking unit for blending with the tertiary butyl alcohol and tertiary butyl acetate.

Preferably, the esterification of the acetic or propoinic acid with tertiary butyl alcohol is carried out at a temperature below l60F., and more preferably below 120F. to aid in avoiding dehydration of the tertiary butyl alcohol to isobutene. Temperatures above about 200F. are not as advantageous for the esterification of the tertiary butyl alcohol with the residual amounts of acid in the presence of the acidic ion exchange resin catalyst used to catalyze the esterification reaction, because at temperatures above 200F. the dehydration of the alcohol can become appreciable. Suitable general conditions for esterification of butyl alcohol with acid are discussed in more detail in U.S. Pat. Nos. 2,644,839, 2,980,731, and 3,384,656, the disclosures of which patents are incorporated by reference into the present specification. According to U.S. Pat. No. 2,644,839 and 3,384,656, the esterification reaction is carried out in the vapor phase. According to U.S. Pat. No. 2,980,731, the esterification reaction is carried out in the liquid phase. In the process of the present invention, it is preferred to carry out the esterification of tertiary butyl alcohol with acetic or propionic acid in theliquid phase. The temperature used in the esterification reaction zone can be between about room temperature and 300F., but more preferably is between about 90F. and 200F. The pressure is preferably sufficient to retain the reactants substantially in the liquid phase and, thus, usually is between about at mospheric pressure and 1000 psig.

For the csterification step of the present invention, preferably a solid catalyst as opposed to a homogenous acid catalyst is used. Preferred catalysts for use in the esterification step of the present invention include relatively high molecular weight water insoluble carbonaceous materials containing sulfonate groups in the form of SO H or -SO;,Na. These catalysts are exemplified by the sulfonated coals (Zeo-Karb H, Nalcite X, and Nalcite AX) produced by the treatment of bituminous coals with sulfuric acid and commercially marketed as zeolitic water softeners or base exchangers.

Other preferred catalysts for the esterification step are the sulfonated resin type catalysts which include the reaction products of phenolformaldehyde resins with sulfuric acid (Amberlite lR-l, Amberlite lR-l00, and Naleite MX). Also useful are the sulfonated resinous polymers of coumarone indene with cyclopentadiene, sulfonated polymers of coumarone indene with furfural, sulfonated polymers of coumarone indene with cyclopentadiene, and furfural and sulfonated poly-- mers of cyclopentadiene with furfural. The most preferred cationic exchange resins are exchange resins consisting essentially of sulfonated polystyrene resin, for instance, a divinylbenzene cross-linked polystyrene matrix having about 0.5 to 20 percent, preferably about 4 to 16 percent, of copolymerized divinylbenzene therein to which are attached ionizable or functional nuclear sulfonate groups. These resins are manufactured and sold commercially under varous trade names, c.g., Dowex 50, Nalcite HCR, and Amberlyst 15.

The resin particle size is chosen with a view of the manipulative advantages associated with any particular range of sizes. Although a small size (200 400 mesh) is frequently employed in autoclave runs, a mesh size of 50 or coarser seems more favorable for use in fixed bed or slurry reactors.

Thus, according to a preferred embodiment of the present invention, the catalyst comprises a resin containing a sulfonate group. According to a particularly preferred embodiment of the present invention, the catalyst comprises a divinyl benzene cross-linked polystyrene matrix, having about 0.5 to 20 percent of copolymcrized divinylbenzene by weight of the catalyst to which is attached sulfonate groups, and having a macroreticular structure.

The term macroreticular is used herein to connote a resin catalyst pore structure having a high degree of I true porosity, that is, pores which are rigid and fixed within the resin beads. The high porosity gives rise to a large surface area which is conducive to high catalytic activity. Amberlyst 15 is a particularly preferred divinylbenze catalyst for use in the process of the present invention. The macroreticular structure in Amberlyst l5 permits ready access of reactants to the sulfonate groups or ions present throughout the resin catalyst beads. This accessibility is not generally found in conventional ion-exchange resins.

For the isobutane oxidation step, according to the process of the present invention cobalt acetate has been found to be a preferred catalyst for use in an acetic acid or propionic acid solvent or carrier. The cobalt acetate catalyst retains relatively high activity for isobutane oxidation at temperatures of about 200 300F., and pressures of about 500 2000 psig for a substantially longer time when the cobalt acetate catalyst is used together with acetic acid. The tertiary butyl alcohol which is produced by the oxidation of the isobutane is separated relatively easily from the cobalt acetate catalyst, but usually a small amount of acetic acid impurity remains in the tertiary butyl alcohol product. It is desirable to remove the acetic acid from the tertiary butyl alcohol before the tertiary butyl alcohol is blended with gasoline boiling range hydrocarbons because the acetic acid is a corrosive agent which can cause subsequent problems in storage and in use of the gasoline. The process of the present invention serves a number of objectives including the elimination of substantially all of the acetic acid from the tertiary butyl alcohol produced in the oxidation of isobutane in the presence of acetic acid.

According to a particularly preferred embodiment of the present invention, a process is provided for producing a high octane unleaded or low lead content gasoline which comprises (a) oxidizing isobutane in a reaction zone in the presence of a cobalt acetate catalyst to obtain 0.1 to 30 liquid volume percent based on the total volume in the reaction zone of tertiary butyl alcohol containing acetic acid, (b) separating a portion of the acetic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing between 50 parts per million and 20,000 parts per million of acetic acid by weight, (c) contacting the tertiary butyl alcohol containing between 50 and 20,000 parts per million of acetic acid with an acidic ion exchange resin catalyst comprising a divinylbenzene cross-linked polystyrene matrix, having about 0.5 to 20 percent of copolymerized divinylbenzene by weight of the catalyst to which is attached sulfonate groups, and having a macroreticular structure to catalyze the esterification reaction of a sufficientamount of the acetic acid with the tertiary butyl alcohol to obtain tertiary butyl acetate and water with unreacted tertiary butyl alcohol containing less than 50 parts per million acetic acid, (d) blending the mixture of tertiary butyl alcohol containing t-butyl acetate and water and less than 50 parts per million acetic acid with gasoline boiling rangehydrocarbons boiling between about 25F. and 450F. to obtain a blend containing between 0.5 and 10, volume percent t'butyl alcohol and ().l and 5.0 volume percent t-butyl acetate, and (e) separating water from the blend to obtain a high octane gasoline. Eropionic acid can also be advantageously used in the above case directed to acetic acid. t

The gasoline produced in accordance with the present invention typically has an octane rating between 80 and 1 l5, and usually between about 90 and 105. Preferably, there are no lead compound additives such as tetra ethyl lead in the gasoline. However, the gasoline can contain a low amount of lead additive, below 3 cc. per gallon, and usually below about 1.5 or l.O cc. lead additive per gallon of gasoline.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a schematic process flow diagram illustrating a preferred embodiment of the combination process of the present invention.

DETAILED DESCRIPTION Referring now more particularly to the drawing, a butane stream is introduced via line 1 to butane oxidation zone 2. Preferably, the butane stream is obtained from a hydrocracking unit. As indicated previously, the process of the present invention is particularly advantageously employed in a refinery containing a hydrocracking unit as the hydrocracking unit produces, in many instances, excess amounts of isobutane and the hydrocracking unit also produces gasoline boiling range hydrocarbons which advantageously are blended with the butyl alcohol and butyl acetate produced as is schematically indicated in the process flow diagram. Hydrocracking processes and suitable catalysts and operating conditions for hydrocracking processes producing substantial amounts of isobutane and also gasoline boiling range hydrocarbons are discussed in US. Pats. No. 2,944,006 and 3,425,934, the disclosures of which patents are incorporated by reference into the present specification. Typical catalysts used for hydrocracking contain a Group VIIIB metal component and sometimes also a Group VIB metal component eogelled with or deposited on a support such as silica-alumina or alumina acidified with small amounts of fluorine. Because of the acidity of the hydrocracking catalyst, the butanes produced in hydrocracking usually consist of about 4 parts isobutane to 1 part normal butane. Because of the large amount of isobutane present in the butane fraction from hydrocracking, the butanes from hydrocracking are a preferred feedstock for the butane oxidation step of the present invention as it is preferred to produce tertiary butyl alcohol in the butane oxidation zone rather than normal or secondary butanol as would be obtained from normal butane.

Referring again more particularly to the drawing, oxygen or air is introduced via line 3 and butane oxidation catalyst together with the preferred acetic acid solvent is introduced via lines 4 and 5 to the oxidation zone. Preferably, the catalyst used for the oxidation is a cobalt acetate catalyst and preferred conditions for the oxidation include a temperature between about 240 and 260F., a pressure between about 600 and 700 psig, an isobutane to solvent volume ratio of about 2:1, and a concentration of cobalt acetate in the acetic acid of about 1.5 weight percent.

The effluent from the butane oxidation zone is passed via line 6 to separation zone 7 wherein acetic acid is separated from the tertiary butanol product for recycle via line 8 to the oxidation zone.

Butyl alcohol containing residual amounts of acetic acid are passed via line 9 to esterification zone 10 for elimination of substantially all of the acetic acid from the butyl alcohol in accordance with the process of the present invention by esterification of the acetic acid with the butyl alcohol using a solid acidic ion exchange resin catalyst to catalyze the reaction. Usually, the butyl alcohol will be at least mostly tertiary butyl alcohol produced from the oxidation of isobutane, and preferably the butyl alcohol is percent or more tertiary butyl alcohol. Additional butyl alcohol can be added to esterification zone 10 to aid in forcing to the right the reaction:

Butyl Alcohol Acetic Acid Butyl Acetate Water As indicated previously, preferred esterification catalysts for use in the esterification zone 10 are acetic sulfonated resins and particularly preferred is Amberlyst 15 which is a divinylbenzene cross-linked polystyrene matrix, having between 0.5 20 percent of copolymerized divinylbenzene by weight of the resin catalyst to which is attached sulfonate groups, and having a macroreticular structure. More specifically, Amberlyst 15 has the following properties:

Property Amberlyst 15 Appearance hard, spherical.

darlvbrown, particles,

toluene-saturated Typical particle size distribution, percent retained on:

Io mesh US. Standard Screens 2.4 -16 20 mesh US. Standard Screens 24.2 -20 30 mesh US. Standard Screens 47.9 30 40 mesh U.S. Standard Screens 18.8 40 50 mesh US. Standard Screens 5.7 Through 50 mesh, percent l O max Whole bead content, 100 Bulk density, g/l as supplied 850 lbs/cu. ft. 54 True density, g/ml as supplied 1.4 Moisture, by weight less than 1% Solids. r 55 60 Percentage swelling from dry state to solvcnt-saturated state hexane 12 toluene l5 ethylene dichloride l7 ethyl acetate 35 ethyl alcohol 66 water 66 Hydrogen ion concentration meq/g. dry 4.9 Surface Area, m'-/g. 40 50 Porosity, ml. pore/ml. bead .30 .35 Average Pore Diameter, Angstroms 200 600 Amberlyst 15 is further described in Bulletin IE-64- 62, February 1962, titled Amberlyst 15 Synthetic Resin Catalyst Technical Notes, and published by the Rohm and Hass Company.

The butyl acetate, which is usually primarily tertiary butyl acetate, is withdrawn from esterification zone 10 via line 12 together with butyl alcohol, usually primarily tertiary butyl alcohol, and water. Because the combination process of the present invention is primarily directed to elimination of small amounts of acetic acid impurities in the tertiary butyl alcohol product from the oxidation step, usually only a small amount of butyl acetate is produced in zone 10 and, thus, the amount of butyl acetate in the mixture withdrawn via line 12 usually is no more than a few tenths volume percent, as for example, 0.5 volume percent or less butyl acetate.

The mixture of butyl alcohol, butyl acetate and water is fed to blending and separation zone 13 wherein gasoline boiling range hydrocarbons are blended with the alcohol-esterwater mixture and water is separated to allow recovery of a high octane gasoline containing no more than trace amounts of acetic acid and containing only small amounts of water.

The term gasoline boiling range hydrocarbons is meant to include hydrocarbons boiling between about 25F. and 475F. As indicated previously, preferably at least a portion of the gasoline boiling range hydrocarbons are obtained from hydrocracking. Hydrocrackate gasoline can be substantially increased in octane by the process of the present invention. The hydrocarbons also can be obtained at least in part from catalytic cracking such as fluidized catalytic cracking or from alkylation such as sulfuric acid or hydrofluoric acid alkylation.

The water can be removed from the butyl alcohol, butyl acetate, water mixture by various means including distillation means such as extractive distillation processes as disclosed in US. Pat. No. 2,591,672 and US. Pat. No. 3,052,731. US. Pat. No. 2,038,357 discloses a process for removal or elimination'of water from alcohol-water mixtures by reacting the water with an added ether in a hydration reaction to form an alcohol. This means of eliminating the water can be combined with the process of the present invention as we have found cthers such as t-butyl methyl ether to be effective components for increasing the octane of unleaded or low lead content gasoline. Thus, unreacted ether can advantageously be left in the product high octaine gasoline, while, at the same time, the alcohol which is produced in water-ether reaction will be effective in increasing the octane of the product gasoline.

According to a preferred embodiment of the process of the present invention, at least the majority of the water is separated from the alcohol-ester-water mixture by settling out the water after blending the alcoholester-water mixture with gasoline boiling range hydrocarbons.

Because the tertiary butyl acetate is present only in relatively small amounts in the alcohol-ester-water mixture blended with the gasoline boiling range hydrocarbons, and because the ester is relatively more soluble in the organic phase than in the aqueous phase, the separation of the water from the hydrocarbon phase can be carried out effectively with the butyl acetate present in addition to the alcohols.

Although various specific embodiments of the invention have been described and shown, it is to be understood that they are meant to be illustrative only and not limiting. Certain features may be changed without departing from the spirit or scope of the invention. It is apparent that the present invention has broad application to the production of high octane fuels by a combination process involving butane oxidation in the presence of an organic acid and subsequent esterification of the organic acid. Accordingly, the invention is not to be construed as limited to the specific embodiments illustrated, but only as defined in the appended claims or substantial equivalents of the claims.

We claim:

1. A process for producing a high octane unleaded or low lead content gasoline which comprises:

a. oxidizing isobutane in the presence of acetic acid to obtain tertiary butyl alcohol containing acetic acid.

b. separating a portion of the acetic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing residual amounts of acetic acid,

c. contacting the tertiary butyl alcohol containing residual amounts of acetic acid with an acidic ion exchange resin catalyst to catalyze the esterification reaction of the residual amounts of acetic acid with tertiary butyl alcohol to obtain t-butyl acetate and water with unreacted tertiary butyl alcohol,

(1. blending the mixture of tertiary butyl alcohol containing t-butyl acetate and water with gasoline boiling range hydrocarbons, and

e. separating water from the blend to obtain a high octane gasoline.

2. A process for producing a high octane unleaded or low lead content gasoline which comprises:

a. oxidizing isobutane in the presence of propionic acid to obtain tertiary butyl alcohol containing propionic acid,

b. separating a portion of the propionic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing residual amounts of propionic acid,

c. contacting the tertiary butyl alcohol containing residual amounts of propionic acid with an acidic ion exchange resin catalyst to catalyze the esterification reaction of the residual amounts of propionic acid with tertiary butyl alcohol to obtain tbutyl propionate and water with unreacted tertiary butyl alcohol,

d. blending the mixture of tertiary butyl alcohol containing t-butyl propionate and water with gasoline boiling range hydrocarbons, and

e. separating water from the blend to obtain a high octane gasoline.

3. A process in accordance with claim 1 wherein the esterification reaction is carried out at a temperature below about F.

4. A process in accordance with claim 1 wherein the acidic ion exchange resin catalyst is a sulfonated resin.

5. A process in accordance with claim 1 wherein the catalyst comprises a divinylbenzene cross-linked polystyrene matrix, having about 0.5 to 20 percent of copolymerized divinylbenzene by weight of the catalyst to which is attached sulfonate groups, and having a macroreticular structure.

6. A process in accordance with claim 1 wherein the tertiary butyl alcohol which is blended with the gasoline also contains C and C alcohols and wherein the water is separated from the t-butyl alcohol-t-butyl acetate-gasoline mixture by settling.

7. A process for producing a high octane unleaded or low lead content gasoline which comprises:

a. oxidizing isobutane in a reaction zone in the presence of a cobalt acetate catalyst to obtain 0.1 to 30 liquid volumepercent based on the total volume in the reaction zone of tertiary butyl alcohol containing acetic acid,

9 10 b. separating a portion of the acetic acid from the tert-butyl acetate and water and unreacted tertiary y butyl Obtain yl alcohol butyl alcohol containing less than 50 parts per milcontaining between 50 parts per million and acetic acid 20900 Part5 P minim of acetic acid by weight d. blending the mixture of tertiary butyl alcohol conc. contacting the tertiary butyl alcohol containing be- 5 mining bbuwl acetate water and less than 50 tween 50 and zo'ooo parts per of parts per million acetic acid with gasoline boiling acid with an acidic ion exchange resin catalyst comprising a divinylbenzene cross-linked polystyrene matrix. having about 0.5 to percent of copolymerized divinylbenzene by weight of the m 0.5 and volume percent t-butyl alcohol and .01 lyst to which is attached sulfonate groups, and havand Volume Pemem y acetate, and

ing a macroreticular structure to catalyze the estersepal'ating Water the blend Obtain a high ification reaction of a sufficient amount of the ane ga o e.

acetic acid with the tertiary butyl alcohol to obtain range hydrocarbons boiling between about 25F. and 450F. to obtain a blend containing between UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3,903,251

DATED September 2, 1975 lN\/ ENTOR(S) 1 Robert P. Sieg and Robert H. Kozlowski It is certified that error appars in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title Page, [73] Canadian Industries Ltd., Montreal, Canada should read -[73] Chevron Research Company, San Francisco,

Calif.-

Col. 7, line 40, "octaine" should read -octane-,

Bigncd and Scaled this sixteenth D3) Of December 1975 [SEAL] A ttes t:

RUTH C. MASON (I. MARSHALL DANN Arresting Officer Commissioner of Patents and Trademarks 

1. A PROCESS FOR PRODUCING A HIGH OCTANE UNLEADED OR LOW LEAD CONTENT GASOLINE WHICH COMPRISES: A. OXIDIZING ISOBUTANE IN THE PRESENCE OF ACETIC ACID TO OBTAIN TERTIARY BUTYL ALCOHOL CONTAINING ACETIC SACID B. SEPERATING A PORTION OF THE ACETIC ACID FROM THE TERTIARY BUTYL ALCOHOL TO OBTAIN TERTIARY BUTYL ALCOHOL CONTAINING RESIDUAL AMOUNT OF ACETIC ACID C. CONTACTING THE TERTIARY BUTYL ALCOHOL CONTAINING RESIDUAL AMOUNTS OF ACETIC ACID WITH AN ACIDIC ION EXCHANGE RESI N CATALYST THE ESTERIFICATION REACTION OF HE RESIDUAL AMOUNTS OF ACETICACID WITH TERTIARY BUTYL ALCHOL TO OBTAIN T-BUTYL ACETATE AND WATER WITH UNREACTED TERTIARY BUTYL ALCOHOL. D. BLENDING THE MIXTURE OF TERTIARY BUTYL ALCOHOL CONTAINING T-BUTYL ACETATE AND WATER WITH GASOLINE BOILING RANGE HYDROCARBONS, AND C. SEPERATING WATER FROM THE BLEND TO OBTAIN A HIGH OCTANE GASOLINE.
 2. A process for producing a high octane unleaded or low lead content gasoline which comprises: a. oxidizing isobutane in the presence of propionic acid to obtain tertiary butyl alcohol containing propionic acid, b. separating a portion of the propionic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing residual amounts of propionic acid, c. contacting the tertiary butyl alcohol containing residual amounts of propionic acid with an acidic ion exchange resin catalyst to catalyze the esterification reaction of the residual amounts of propiOnic acid with tertiary butyl alcohol to obtain t-butyl propionate and water with unreacted tertiary butyl alcohol, d. blending the mixture of tertiary butyl alcohol containing t-butyl propionate and water with gasoline boiling range hydrocarbons, and e. separating water from the blend to obtain a high octane gasoline.
 3. A process in accordance with claim 1 wherein the esterification reaction is carried out at a temperature below about 160*F.
 4. A process in accordance with claim 1 wherein the acidic ion exchange resin catalyst is a sulfonated resin.
 5. A process in accordance with claim 1 wherein the catalyst comprises a divinylbenzene cross-linked polystyrene matrix, having about 0.5 to 20 percent of copolymerized divinylbenzene by weight of the catalyst to which is attached sulfonate groups, and having a macroreticular structure.
 6. A process in accordance with claim 1 wherein the tertiary butyl alcohol which is blended with the gasoline also contains C3 and C5 alcohols and wherein the water is separated from the t-butyl alcohol-t-butyl acetate-gasoline mixture by settling.
 7. A process for producing a high octane unleaded or low lead content gasoline which comprises: a. oxidizing isobutane in a reaction zone in the presence of a cobalt acetate catalyst to obtain 0.1 to 30 liquid volume percent based on the total volume in the reaction zone of tertiary butyl alcohol containing acetic acid, b. separating a portion of the acetic acid from the tertiary butyl alcohol to obtain tertiary butyl alcohol containing between 50 parts per million and 20,000 parts per million of acetic acid by weight, c. contacting the tertiary butyl alcohol containing between 50 and 20,000 parts per million of acetic acid with an acidic ion exchange resin catalyst comprising a divinylbenzene cross-linked polystyrene matrix, having about 0.5 to 20 percent of copolymerized divinylbenzene by weight of the catalyst to which is attached sulfonate groups, and having a macroreticular structure to catalyze the esterification reaction of a sufficient amount of the acetic acid with the tertiary butyl alcohol to obtain t-butyl acetate and water and unreacted tertiary butyl alcohol containing less than 50 parts per million acetic acid, d. blending the mixture of tertiary butyl alcohol containing t-butyl acetate and water and less than 50 parts per million acetic acid with gasoline boiling range hydrocarbons boiling between about 25*F. and 450*F. to obtain a blend containing between 0.5 and 25 volume percent t-butyl alcohol and .01 and 5.0 volume percent t-butyl acetate, and e. separating water from the blend to obtain a high octane gasoline. 